The present invention relates generally to a heat reclaiming method and apparatus, and more particularly to a method and apparatus for reclaiming the normally wasted heat rejected by the refrigerant of a refrigeration circuit.
Vapor compression refrigeration systems generally comprise a compressor, a condenser, an expansion device, and an evaporator connected by appropriate refrigerant lines to form a refrigeration circuit. Refrigerant vapor is compressed by the compressor and fed to the condenser where the refrigerant rejects heat to a cooling medium and condenses. The condensed refrigerant then flows through the expansion device, reducing the pressure and temperature of the refrigerant. From the expansion device, the refrigerant passes into the evaporator, absorbs heat from a medium which is thereby cooled, and vaporizes. Vaporous refrigerant is then drawn back into the compressor, completing the circuit.
Refrigeration circuits of the foregoing type are frequently employed to cool a fluid such as water which is circulated through various rooms or areas of a building to, in turn, cool these areas. Often, the refrigerant of such circuits rejects a relatively large amount of heat at the condenser of the circuit. This rejected heat is commonly dissipated to the atmosphere, either directly or via a cooling fluid that circulates between the condenser and a cooling tower. Over a period of time, the rejected heat represents a substantial waste or energy, and recently much attention has been directed to reclaiming or recovering this heat.
One general approach to reclaiming this heat has been to draw off a portion of the refrigerant vapor discharged from the compressor and pass this vapor through a heat reclaiming condenser separate from the condenser of the refrigeration circuit. A heat exchanger comprising a plurality of heat exchange tubes is positioned within the heat reclaiming condenser, and water is circulated through the heat exchanger in heat transfer relation with the vapor in the heat reclaiming condenser. Heat is transferred from the vapor to the water, heating the water and condensing the vapor. The heated water is conducted to a storage tank where the water may be stored for later use, and the condensed refrigerant is returned to the refrigeration circuit for further use therein. Under certain circumstances, condensed refrigerant may accumulate in the heat reclaiming condenser and flood tubes of the heat exchanger located therein. When this happens, water passing through the flooded tubes does not come into direct heat transfer relation with the refrigerant vapor which is much hotter than the liquid, condensed refrigerant. As a result, the amount of heat absorbed by the water is reduced, reducing the amount of heat reclaimed from the refrigeration circuit.